1. Technical Field
The present invention relates to an image display system, and in particular relates to an image display system having an organic electroluminescent device.
2. Description of the Related Art
Organic light-emitting diodes (OLED) use an organic electroluminescent layer. The trend in organic electroluminescent display technology is for higher luminescent efficiency and longer lifetime. As a result, an active matrix organic electroluminescent device with thin film transistors has been developed. The active matrix organic electroluminescent device has panel luminescence with thin and lightweight characteristics, spontaneous luminescence with high luminescent efficiency and low driving voltage, and advantages of increased viewing angle, high contrast, high-response speed, and full color. However, since the organic electroluminescent device is easily damaged by ambient humidity and air penetration, the organic electroluminescent device has poor stability in general.
Therefore, in the fabrication of the organic electroluminescent device, a sealing process for protecting the organic electroluminescent pixels array of the organic electroluminescent device from the outside may be performed. For example, a sealant such as an epoxy resin is disposed on the edges of am encapsulating cover for encapsulating the organic electroluminescent device, and the encapsulating cover has a cavity for containing an absorbent. However, since it is not possible to completely prevent moisture and oxygen from permeating from the outside into the organic electroluminescent device by the above-described methods, the organic electroluminescent device may be deteriorated after operating for a period of time.
In order to solve the aforementioned problem, an organic electroluminescent device 10 sealed with a low-melting sealing glass has been disclosed. Please referring to FIG. 1, the organic electroluminescent device 10 has a substrate 12, and an organic electroluminescent pixels array 14 is formed on the substrate 12. A package substrate 16 is disposed opposite to the substrate 12, and a low-melting sealing glass 18 is used to seal the substrate 12 with the package substrate 16, defining a space containing the organic electroluminescent pixels array 14. It should be noted that, since the low-melting sealing glass is cured by a laser curing process, the low-melting sealing glass 18 should be separated with a predetermined distance D from the organic electroluminescent pixels array 14 (forming a gap 15) in order to prevent the organic electroluminescent pixels array 14 from the heat generated during the laser curing process. Further, the organic electroluminescent device 10 must have a polarizing film 12 disposed on the package substrate 16, in order to prevent the reflective ambient light (incident from the gap 15 and passed through the low-melting sealing glass) from degrading the display performance of the organic electroluminescent device 10. However, the additional process for forming the polarizing film results in a longer manufacturing time and higher cost and reduces the yield of the organic electroluminescent device.
Therefore, a novel organic electroluminescent device which overcomes the above problems is desired